Reflection Exception for hello world program

By Krati Shah on 20 Nov 2014 at 12:58 UTC

I am new to Drupal. i start with working on Drupal 8. I created one custom module on Hello world.Very Basic .
Getting Below Error.
ReflectionException: Class \Drupal\helloworld\Controller\HelloWorldController does not exist in ReflectionMethod->__construct() (line 132 of core\lib\Drupal\Core\Entity\EntityResolverManager.php).

Here is my Controller file.

<?php
/**
* @file
* Contains \Drupal\helloworld\Controller\HelloWorldController.
*/
namespace Drupal\helloworld\Controller;
use Drupal\Core\Controller\ControllerBase;
/**
* Controller routines for hello module routes.
*/
class HelloWorldController extends ControllerBase {
/**
* Return the 'Hello World' page.
*
* @return string
* A render array containing our 'Hello World' page content.
*/
public function display_text() {
$output = array();
$output['hello'] = array(
'#markup' => 'Hello World!',
);
return $output;
}
}

helloworld.routing.yml:

helloworld.hello_world:
path: '/helloworld'
defaults:
_content: '\Drupal\helloworld\Controller\HelloWorldController::display_text'
requirements:
_permission: 'view helloworld'

Comments

@karthi, have you kept the

dhruba.jyoti.saha commented 26 November 2014 at 12:26

@karthi, have you kept the HelloWorldController.php file inside helloworld/src/Controller folder?

Can see one extra '<?php' tag.

I had the same probleme

elhousny commented 31 May 2016 at 20:39

Hi,
I had the same problem, do you have any suggestion.

Cheers,
Hicham

Case sensitive?

idflood commented 23 October 2015 at 05:45

I had the same issue on a production server and it was caused by the fact that my controller folder was all lowercase but it needed to be "Controller".

David Mignot
www.idflood.com
gittip

fml src

farse commented 31 August 2017 at 14:18

I had the same problem too and just realised that my 'src' folder was called 'scr' :/

Exactly

gzveri commented 9 February 2018 at 16:53

I had the exact same problem and renaming "controller" folder inside my module into "Controller" - has fixed it . Thank you for the tip.

Me too

ancoss commented 10 April 2019 at 10:39

I had the same problem in Ubuntu and changing "controller" to "Controller" - fixed. Thanks.

Got similar error with a form

aangel commented 2 June 2016 at 15:11

And was missing:
use Symfony\Component\HttpFoundation\Request;

This for me too, but the docs

NikLP commented 14 June 2016 at 14:55

This for me too, but the docs don't explain why it's required?

Drupal Build & Development in Nottingham by Kineta Systems

@Krati Shah: Controller file kept in wrong folder

farooq.salmani commented 5 August 2016 at 11:41

It appears that you have kept your controller in wrong folder. Make sure that your controller file path is helloworld/src/Cotroller/HelloWorldController.php.

perfect..thanks..

prakash.d commented 18 August 2018 at 06:20

perfect..thanks..

_content: '\Drupal\helloworld

joshi.rohit100

he/him

Hindi

Delhi, India

commented 8 August 2016 at 08:40

_content: '\Drupal\helloworld\Controller\HelloWorldController::display_text'

shouldn't _content key be _controller?

Lowercase error

stefvanlooveren commented 1 January 2017 at 15:04

I encoutered this error because I wrote Drupal lowercase in my .routing.yml file.
So instead of _controller: \drupal\helloworld\Controller\HelloWorldController::display_text
I had to use _controller: \Drupal\helloworld\Controller\HelloWorldController::display_text

Uppercase Error

ImCrazy commented 2 August 2018 at 12:07

I was going crazy with Drupal crashing and throwing an error drupal 8 class="placeholder">InvalidArgumentException...etc when trying to run a form. I was typing the text exactly as the example videos on youtube showed but it kept crashing.

Thanks to Stegvanlooverens comments, I checked my directory and file names, and realised that my 'src' directory had capital S (i.e. Src). Renamed it with a lowercase 's' and it worked perfectly. Days of frustration because of a uppercase S in the directory structure. Check your files and folders, and remember that YAML is case sensitive.

i also geting same error

Vikash raj commented 9 February 2017 at 07:02

hello guys, i made a custome module in drupal 8 for insert update and delete with drupal admin link menu now i want sorting and paging in that list so i try to use
http://stackoverflow.com/questions/40234134/how-to-use-select-query-for-...

but when i try to install this module then i m geeting error

The website encountered an unexpected error. Please try again later.

Drupal\Component\Serialization\Exception\InvalidDataTypeException: Malformed inline YAML string ('Access students list page) at line 2 (near "title: 'Access students list page"). in Drupal\Component\Serialization\YamlSymfony::decode() (line 39 of core/lib/Drupal/Component/Serialization/YamlSymfony.php).

Symfony\Component\Yaml\Inline::parseScalar(''Access students list page', NULL, Array, 0, 1, Array) (Line: 71)
Symfony\Component\Yaml\Inline::parse(''Access students list page', 1, , , Array) (Line: 506)
Symfony\Component\Yaml\Parser->parseValue(''Access students list page', 1, , , 'mapping') (Line: 233)
Symfony\Component\Yaml\Parser->parse('title: 'Access students list page', 1, , ) (Line: 225)
Symfony\Component\Yaml\Parser->parse('access students list:
title: 'Access students list page', 1, ) (Line: 36)
Drupal\Component\Serialization\YamlSymfony::decode('access students list:
title: 'Access students list page') (Line: 35)
Drupal\Component\Serialization\Yaml::decode('access students list:
title: 'Access students list page') (Line: 19)

pleease help

@vikas - As per the the

joshi.rohit100

he/him

Hindi

Delhi, India

commented 9 February 2017 at 07:09

@vikas - As per the the warning, looks like your yaml syntax in not correct. Either just copy this from existing one or just remove your permission yml and update routing.yml file as weel then clera cache and check.

missing <?php at the top

albertomota commented 7 July 2017 at 21:59

made the same mistake.. the sample code is missing the <?php tag at the top, updated the documentation page to include it now so hopefully others won't hit the same error..

@Krati and anyone new facing this problem

fngatia commented 18 August 2017 at 02:07

I remember one time faced with similar problem and found out that this error is caused due to wrong yml files naming. This is what i mean:

1. namespace is CASE SENSITIVE. Check this.
2. Your module yml names should match the Name of the module. For instant if your module is HelloWorld, your yml files should match too: HelloWorld.info.yml, HelloWorld.links.menu.yml, HelloWorld.routing.yml. This will not work: helloworld.info.yml, helloworld.links.menu.yml, helloworld.routing.yml
3. If your change the yml files, the module will be disabled. Go to your Extend and enable.
Always remember to clear cache after the changes.

Fixed the error after hours of trying to figure out

ramyanarayanan commented 13 September 2017 at 15:43

Adding to the already existing solutions, the issue with me was that the Module name and the config form name did not match. The module name in the yml file had to be matched to the form file name.

name: MyPoject Domain Field Settings
description: 'MyPoject Domain Field Settings'

routing.yml
defaults:
_form: '\Drupal\ex_domain_field_access\Form\MyPojectDomainFieldSettingsForm'

src/Form:
MyPojectDomainFieldSettingsForm.php'

I had a similar error.

marco-s

Switzerland🇨🇭

commented 19 December 2017 at 11:21

I had a similar error.

ReflectionException: Class \Drupal\xyz_account\Controller\XyzAccountController does not exist in /var/www/example.com/docroot/core/lib/Drupal/Core/Entity/EntityResolverManager.php:123

In my case I had a wrong route name in my MODULE.routing.yml.

xyz_account.routing.yml

xyz_account.login:
  path: '/login'
  ...
xyz_events.list:
  path: '/events/list'
  ...

The route name have to match the module name.

@marco-s - route name have to

joshi.rohit100

he/him

Hindi

Delhi, India

commented 19 December 2017 at 14:27

@marco-s - route name have to match with module name this is not required. Only requirement is that ur route name should be uniqueue and follow some naming convention. There are many reasons for this error. Like - class name/file name is not matching. Class name and file name should be same and as what defined in routing.yml. Second reason can be that ur class file is not in correct directory. Another reason can be that you have not added namespace in your class.

I had defined a _controller parameter for each route

marco-s

Switzerland🇨🇭

commented 20 December 2017 at 08:32

@joshi.rohit100 - yes, I am sorry, I didn't give enough information in my last post. I had defined a _controller parameter for each route. That was the reason for the error (Class name/file matching etc. were correct). Therefore, I had to move the xyz_event.list route to the xyz_event.routing.yml file in my xyz_event module folder.

xyz_account.login:
  path: '/login'
  _controller: '\Drupal\xyz_account\Controller\XyzAccountController::login'
  ...
xyz_event.list:
  path: '/events/list'
  _controller: '\Drupal\xyz_event\Controller\XyzEventController::list'
  ...

Syntax errors can do this

jmuzz commented 9 May 2018 at 13:34

If your controller file has a syntax error you can get this message that the class does not exist. In my case it was a misplaced semicolon. The error it displayed did not give any indication that there was a syntax error. You can test your controller for syntax errors by running your controller file with CLI php. If that gives you a syntax error it will have details you can use to fix it. If you get a different error then it probably won't be helpful.

Good catch, thanks for the

kufeiko commented 22 September 2018 at 15:49

Good catch, thanks for the hint.

Exactly

mithesh.kavrani commented 5 March 2020 at 07:06

Had a syntax error of missing coma.

Syntax error can be found if you use drush to clear cache after you get this error, or use drush to enable module.

Thanks!

Above comment for syntax

suresh.gju commented 15 August 2018 at 12:23

Above comment for syntax error is the issue for me. Just comment most code and run. Once it works then uncomment function by function

I think this is indicative of

jayemel commented 4 December 2018 at 18:26

I think this is indicative of how overly complicated Drupal has become with 8. When the most basic programming lesson for Drupal 8 causes so much confusion over case and naming and directory naming -- It's just too much.

Well, it depends on what you

Jaypan commented 7 December 2018 at 06:43

Well, it depends on what you consider overly complicated. If you are looking for something easier to get into on a programming level, and don't need the power of Drupal's architecture, then yes, it's overly complicated. Wordpress is a much better fit for this type of situation. If you need an Enterprise level system however, Drupal is not overly complicated, it's actually an amazingly architected system. That complexity you are facing isn't there simply to make it difficult, it's built the way it is for a reason.

I've been working with Drupal

jayemel commented 10 December 2018 at 18:29

I've been working with Drupal for years on an enterprise level, and I always expect it to be sometimes an easy and rewarding experience, and often a frustrating one. My comment was hasty, and I actually think d8 is very well structured with 8. My major gripe, I guess, is that documentation for basic functionality is often poor, missing, or incomplete, which increases the complexity for veterans and beginners alike.

Am agree with @jmljunior

mangesh_sathe_pune commented 27 May 2019 at 11:14

Am agree with @jmljunior. Drupal 8 is difficult to understand as documentation is vert very poor. There is no common pattern followed while writing its documentation, they don't even have complete documentation for running version D8 and they are planning for D9 release in 2020. Finding it difficult to grasp, but in a weeks time i will cover it up!